package com.usian.admin.gateway.config;

import com.alibaba.nacos.client.utils.StringUtils;
import com.usian.admin.gateway.util.AppJwtUtil;
import io.jsonwebtoken.Claims;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class AuthorizeFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        //1.获取请求对象和响应对象
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
      try {
          //2.判断当前的请求接口是否为登录，如果是，直接放行
          if(request.getURI().getPath().contains("/login/in")){
              //放行
              return chain.filter(exchange);
          }
          //3.获取请求头
          HttpHeaders headers = request.getHeaders();
          String jwtToken = headers.getFirst("token");

          //4.判断当前令牌是否存在
          if(StringUtils.isEmpty(jwtToken)){
              //如果不存在，向客户端返回错误提示信息
              response.setStatusCode(HttpStatus.UNAUTHORIZED);
              return response.setComplete();
          }
          //5.如果令牌存在，解析jwt令牌，判断该令牌是否合法，如果不合法，则向客户端返回错误信息
          Claims claims = AppJwtUtil.getClaimsBody(jwtToken);
          int result = AppJwtUtil.verifyToken(claims);
          if(result == 0 || result == -1){
              //5.1 合法，则向header中重新设置userId
              Integer id = (Integer) claims.get("id");
              //重新设置token到header中
              ServerHttpRequest serverHttpRequest = request.mutate().headers(httpHeaders -> {
                  httpHeaders.add("userId", id + "");
              }).build();
              exchange.mutate().request(serverHttpRequest).build();
          }
      }catch (Exception e){
          e.printStackTrace();
          response.setStatusCode(HttpStatus.UNAUTHORIZED);
          return response.setComplete();
      }

        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
